1. Field of the Invention
This Invention relates to an extraction trap device and method of operation thereof and more particularly to a syringe-like device having a needle with a trap located in the needle whereby particulate matter can be collected and directly desorbed into an analytical instrument.
2. Description of the Prior Art
The environmental impact, chemical composition, concentration trends, and health effects of airborne particulate matter have been extensively studied and described in the literature. Current sampling methods involve the use of gravimetric filters or impactor devices, and a wide variety of light and laser scattering devices. Many of the analytical methods for determination of chemical composition of airborne particulate matter require either sophisticated equipment and/or use strict sample preparation techniques. The task of sampling and analysis of airborne particulate matter is often complicated by the complexity of particle size, particle interactions, chemical partitioning between gaseous and particulate phase, and interactions with the sampling media. The health effects of inhaled particulate matter are associated with both the size and shape, as well as chemical toxicity. One of the better known groups of analytes from the latter category are polycyclic aromatic hydrocarbons.
Polycyclic aromatic hydrocarbons (PAH""s) have received increased attention in recent years due to their suspected carcinogenic and/or mutagenic nature. Polycyclic aromatic hydrocarbons originate in incomplete combustion, and are commonly found in gasoline and diesel motor exhaust, as by-products of open fires, industrial smoke, cigarette and cigar tobacco and smoke, and in charcoal-broiled foods. Other sources include coal tar, coal tar pitch, wood preserving agents and coatings, mineral oils, and asphalt.
Current sampling methods for PAH""s involve the use of high-volume pumps, filters and sorbent cartridges, e.g., NIOSH 5506, NIOSH 5515, and EPA TO-13A. These methods require extraction from a filter (or sorbent) with an appropriate solvent, followed by subsequent analysis by high-performance liquid chromatography (HPLC), fluorescence, UV detection, or gas chromatography/mass spectometry (GC/MS). Many of these methods require considerable sampling expertise and sophisticated sampling equipment, long sample collection and sample preparation time, and strict extraction procedures. Thus, there is a growing demand for faster, simpler and cost-effective sampling for analytical methods for airborne PAH""s without compromising low detection limits achievable with some of the conventional methods. In addition, these new techniques should be reusable and environmentally friendly.
The great majority of the analytical methods used for determination of steroids present in inhaler-administered drugs for treatment of asthma use radioimmunoassay protocols, HPLC, and GC combined with MS. However, the latter methods require derivatization prior to injection. Similarly, the sampling and analysis of consumer sprays and aerosols is usually conducted with a sophisticated sampler, or a method is specific to a particular analyte. To date, there is no simple and fast method for screening of a wide variety of many consumer products that are delivered in a form of spray or aerosol.
Solid phase microextraction (SPME) provides an attractive alternative over traditional analytical methods by combining sampling, pre-concentration, and direct (and complete) transfer of the extracted analytes into a standard gas chromatograph (GC). To date, SPME has been successfully applied in numerous environmental applications including air sampling and analysis methods for total volatile organic compounds (TVOC""s) and formaldehyde. Several researchers demonstrated that SPME may also be applied to analysis of PAH""s in water. Only a few researchers indicated that SPME may be applied to air sampling for PAH""s. Chai and Pawliszyn (1995) found naphtalene, phenanthrene, antracene, and fluoranthene by direct exposure of an SPME device in the diesel exhaust.
It is an object of the present invention to provide a device and method of operation thereof whereby sampling can be carried out with a hand held device without the use of chemicals or other components that are ultimately discharged into the environment, pre-concentration and direct and complete transfer of the extracted analytes from the device into an analytical instrument.
A device for sampling and extracting components of interest from air containing particulate matter has a passageway with two ends. One of the ends is a free end and part of the passageway contains a trap for the particulate matter. The trap is located partway between the ends. There are pressure differential means that can cause air to flow through the trap. The pressure differential means are located on the side of the trap opposite to the free end. The passageway is sized to be placed into an injection port of a suitable analytical instrument.
A method of sampling and extracting components of interest from air containing particulate matter uses a device having a passageway with two ends. One of the ends is a free end and there is a trap in the passageway. The device has pressure differential means that can cause air to flow through the trap. The pressure differential means is located on the side of the trap opposite to the free end. The method comprises operating the pressure differential means to draw air into the passageway, subsequently inserting the passageway into an injection port of an analytical instrument, desorbing analytes from the trap into the instrument and analyzing the results obtained from the instrument.